Answer: let the probability of weights less than 160 be the required value, then, using z-score formula
z-score =( x - ∪) ÷ Ф where, x is 160, ∪ is population mean = 175,
Ф is the population standard deviation = 15
z-score = (160 - 175) ÷ 15 = -1
p(z< -1) = 0.159
Step-by-step explanation:
the question is not complete. Assuming that the missing figure is 160 representing the required weights ess than the normal weights of 175.
step 1. obtain the z-score value by using the formula
z =( x - ∪) ÷ Ф
step 2. obtain the probability of weights less than 160 from normal distribution table. since z-score value is -1,the probability is obtained as 0.159 that is 15.9%